NonStop S-Series Hardware Installation and FastPath Guide (G06.25+)

Glossary
HP NonStop S-Series Hardware Installation and FastPath Guide—529443-001
Glossary-27
double-wide plug-in card (PIC)
double-wide plug-in card (PIC). A large-form-factor plug-in card (PIC) that occupies two
adjacent PIC slots within a ServerNet adapter or an HP NonStop™ cluster switch. See
also single-wide plug-in card (PIC).
download. The process of transferring software from one location to another, where the
transferring entity initiates the transfer.
download line task. Any task running under the Portable Silicon Operating System (pSOS)
system product, such as a data protocol.
downtime. Time during which a computer system is not capable of doing useful work
because of a planned or unplanned outage. From the end user’s perspective,
downtime is any time a needed application is not available.
downward compatibility. The ability of a requester to operate with a server of an earlier
revision level. In this case, the requester is downward-compatible with the server, and
the server is upward-compatible with the requester. Contrast with upward compatibility.
DRAM. Dynamic random-access memory.
drive. See disk drive or tape drive.
dropout. A voltage loss of very short duration (that is, milliseconds).
DSC. See Dynamic System Configuration (DSC).
DSM. See Distributed Systems Management (DSM).
DSM/SCM. See Distributed Systems Management/Software Configuration Manager
(DSM/SCM).
DSV. See distribution subvolume (DSV).
DTE. See data terminal equipment (DTE)
.
dual inline memory module (DIMM). Small circuit boards carrying memory integrated
circuits, with signal and power pins on both sides of the board. A DIMM is different
from a single inline memory module (SIMM) in that the connections on each side of the
module connect to different chips, whereas the connections on both sides of a SIMM
connect to the same memory chip. This difference gives the DIMM a wider data path,
as more modules can be accessed at once.
dual-ported. The capability of a ServerNet adapter or peripheral device to receive data and
commands from two sources although only one source might have access at any
particular moment.
duplicate file descriptor. In the Open System Services (OSS) file system, a file descriptor
that refers to the same open file description as another file descriptor.
DWARF. See Debug With Arbitrary Record Format (DWARF)
.